JP2000155248A - Optical fiber ribbon and method for removing coating - Google Patents

Abstract

(57) Abstract: An object of the present invention is to add a new requirement to a collective coating layer, thereby providing an optical fiber ribbon and a coating having more excellent collective removal properties and single-core separation properties. To provide a method for removal of SOLUTION: A protective coating layer 2 is provided on the outer periphery of a glass fiber 1.
Are arranged in parallel with each other, and
An optical fiber ribbon formed by integrating the outer circumference of the protective coating layer with the collective coating layer, wherein the pull-out force between the glass fiber 1 and the protective coating layer 2 is 300 g or more and 1700 g or less; Adhesion force with the collective coating layer 4 is 0.4 g / cm or more and 10 g / cm or less.
The loss tangent of the collective coating layer 4 at 0 ° C to 110 ° C is 0.
05 or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber ribbon and a method for removing the coating therefrom.

[0002]

2. Description of the Related Art Conventionally, optical fiber ribbons have been widely used for the purpose of increasing the density of optical fibers in an optical cable and increasing the efficiency of connection work of the optical cable. FIG. 7 is a view showing a conventional optical fiber tape core wire 5c, in which a primary layer made of a soft ultraviolet curable resin is provided on the outer periphery of an optical fiber 1 made of quartz glass (hereinafter abbreviated as "glass fiber") 1. 2a, a secondary layer 2b made of a hard resin on the outer periphery thereof, and a colored layer 2c on the outer periphery thereof.
Are arranged in parallel with each other, and a collective coating layer 4 made of an ultraviolet-curable resin is arranged on the outer periphery thereof.
Is formed.

In such an optical fiber ribbon 5c, the protective coating layer 2 and the collective coating layer 4 can be simultaneously removed from the glass fiber 1 in order to efficiently connect the optical fiber core wires. The so-called "single-core detachability", and the so-called "single-core detachability" for removing only the collective coating layer 4 near the tip of the optical fiber core 3 and separating and terminating the optical fiber cores 3 respectively. Is required.

[0004] One example of the prior art relating to these problems is:
It is described in JP-A-3-209207. FIG.
In the optical fiber ribbon 5c having the structure shown in FIG. 5, the coating pulling force when the protective coating layer 2 is pulled out from the glass fiber 1 in the longitudinal direction, and the collective coating for the adhesive force between the coloring layer 2c and the collective coating layer 4 It describes the relationship between removability and single-core separation. Also, Japanese Unexamined Patent Application Publication No. 6-31382
In the configuration shown in FIG. 7, the optical fiber tape core wire described in Japanese Patent Application Publication No. 7-1995 does not show the adhesion between the colored layer 2c and the collective coating layer 4 and the strength of the collective coating layer 4 with respect to the breaking strength of the collective coating 4. It describes the relationship between thinning and single core separability.

[0005]

However, according to various studies conducted by the present inventors, Japanese Patent Laid-Open No. 3-209207 is disclosed.
In the optical fiber ribbon 5c described in Japanese Patent Application Laid-Open Publication No. H11-157, the upper limit of the pulling force of the protective coating layer 2 is not specified, so that the protective coating layer 2 may adhere to the glass fiber 1 and remain. Further, even when the adhesive strength between the colored layer 2c and the collective coating 4 is limited to a certain range, only the collective coating layer is peeled off and the protective coating layer remains, or the protective coating layer is bent in a bellows shape. There was a need for improvement.

On the other hand, in the optical fiber ribbon described in JP-A-6-313827, the bulk coating 4 can be made thinner, but the problem of collective removal has not been solved. Therefore, the present inventors have conducted intensive studies and found that by adding further new requirements to the collective coating layer, it is possible to obtain more excellent collective removal properties and single-core separation properties. An object of the present invention is to provide an optical fiber ribbon and a method for removing coating.

[0007]

A first optical fiber ribbon according to the present invention comprises a plurality of optical fiber cores provided with a protective coating layer on the outer periphery of a glass fiber, and the outer periphery thereof is arranged in parallel. In the optical fiber ribbons integrally formed by the collective coating layer, the pull-out force between the glass fiber and the protective coating layer is 300 g or more and 1700 g or less, and the adhesive force between the protective coating layer and the collective coating layer is zero. 0.4g
/ Cm or more and 10 g / cm or less.
The loss tangent of the collective coating layer at 10 ° C. is 0.05 or more.

According to the first optical fiber ribbon, if the pullout force between the glass fiber of the optical fiber core and the protective coating layer is less than 300 g, the glass fiber cannot be stably held. If it exceeds 1700 g, it becomes difficult to remove the protective coating layer from the glass fiber. When the adhesion between the protective coating layer and the collective coating layer is less than 0.4 g / cm, it is difficult to remove the protective coating layer and the collective coating layer at once, and when it exceeds 10 g / cm, the collective coating layer becomes difficult. It becomes difficult to peel the layer from the protective coating layer, and it becomes difficult to ensure single-core separation.

Further, when the loss tangent of the collective coating layer at 70 ° C. to 110 ° C. is less than 0.05, the internal friction of the collective coating layer at 70 ° C. to 110 ° C. due to molecular motion increases from room temperature, and the loss of tangent with the protective coating layer increases. Although unity increases, it is not sufficiently strengthened. When the loss tangent of the collective coating layer at 70 ° C to 110 ° C exceeds 0.05, the integrity of the protective coating layer and the collective coating layer is strengthened, and the collective removal property is further improved. On the other hand, at room temperature, the integrity of the collective coating layer due to the molecular motion of the protective coating layer is released, so that it is easy to remove the collective coating layer from the protective coating layer, and the single-core separation of the optical fiber core is reduced. Secured. Temperature between 70 ° C and 110
The reason why the temperature is limited to 0 ° C. is that a commercially available jig (heating remover) for removing a coating for a tape core wire is 70 ° C. to 11 ° C.
This is because the heating temperature is set to 0 ° C.

When the interface state between the protective coating layer and the collective coating layer is viewed at the atomic level, there are portions where the adhesion is strong and portions where the adhesion is weak. When left in wet heat, moisture starts to accumulate in the weakly adhered portion, and the peeling gradually spreads. However, if the loss tangent is 0.05 or more in a state where the collective coating layer is heated to 70 ° C. or more as in the present invention, molecular motion occurs while maintaining a certain hardness. For this reason, water accumulates at the interface, the molecular motion relaxes the stress that tends to expand, and the spread of cracks is suppressed, so that the glass fiber has a protective effect.

In the second optical fiber ribbon according to the present invention, a plurality of optical fiber cores having a protective coating layer provided on the outer periphery of a glass fiber are arranged in parallel, and the outer periphery is integrated with an inner batch coating layer. A plurality of optical fiber units are formed in parallel and arranged in parallel, and the outer periphery is integrated with an external collective coating layer. The pull-out force is 300 g or more and 1700 g or less, and the adhesion between the protective coating layer and the inner batch coating layer is 0.4 g / cm 10 or more.
g / cm or less, and the loss tangent of the inner collective coating layer and the outer collective coating layer at 70 ° C to 110 ° C is 0.
05 or more.

According to the second optical fiber ribbon, since a plurality of optical fiber units are formed integrally, it is suitable for a configuration in which the number of optical fibers is large. The difference from the configuration of the optical fiber ribbon is that the first optical fiber ribbon is covered with one collective coating layer, whereas the second optical fiber ribbon is 2 It is being covered with one collective covering layer (the inner collective covering layer and the outer collective covering layer). Therefore, the characteristics of the first optical fiber ribbon are all provided for the collective removal of the coating and the single-core separation of the optical fiber.

[0013] In a first method for removing coating of an optical fiber ribbon according to the present invention, a plurality of optical fibers having a protective coating layer provided on the outer periphery of a glass fiber are arranged in parallel.
The outer periphery is formed integrally with the collective coating layer,
The pull-out force between the glass fiber and the protective coating is 3
100 g or more and 1700 g or less, the adhesion between the protective coating layer and the collective coating layer is 0.4 g / cm or more and 10 g / cm or less, and the loss tangent of the collective coating layer at 70 ° C. to 110 ° C. is 0. In the method of removing the coating of the optical fiber ribbon which is not less than 05, the step of heating the optical fiber ribbon, and the protective coating layer and the batch coating layer heated in the heating step are sandwiched by a cutter in a direction substantially perpendicular to the longitudinal direction. The method is characterized in that the method includes a step of making a cut while cutting and a step of moving the cutter in the longitudinal direction of the optical fiber to remove the protective coating layer and the collective coating layer.

According to the first coating removing method, the first coating removing method is used.
What is claimed is: 1. A method for removing a coating on an optical fiber ribbon, comprising: heating a first optical fiber ribbon; cutting a coating while interposing the cutter in a direction substantially perpendicular to a longitudinal direction; And removing in a longitudinal direction of the core wire.

That is, in the first optical fiber ribbon, the force for pulling out the protective coating layer of the optical fiber core and the adhesion between the protective coating layer and the collective coating layer are each limited to predetermined ranges. By heating this optical fiber tape,
The integrity of the collective coating layer and the protective coating layer can be enhanced. In such a state, an axial pulling force is applied to the protective coating layer and the collective coating layer, so that it is easier to remove both the coating layers integrally. Further, at room temperature, since the integrity of the collective coating layer due to the molecular motion is released, the adhesion between the collective coating layer and the protective coating layer is weakened, and the single-core separation characteristic is secured.

According to a second method for removing a coating of an optical fiber ribbon according to the present invention, a plurality of optical fibers having a protective coating layer provided on the outer periphery of a glass fiber are arranged in parallel.
A plurality of optical fiber units formed by integrating the outer periphery with the inner collective coating layer are further arranged in parallel, and the outer periphery is integrally formed with the outer collective coating layer, and the glass fiber and the protective coating layer are formed. 30 pullout force during
0 g or more and 1700 g or less, the adhesion between the protective coating layer and the inner collective coating layer is 0.4 g / cm or more and 10 g / cm or less, and the inner collective coat layer and the outer collective coat layer at 70 ° C. to 110 ° C. A step of heating the optical fiber ribbon, wherein the protective coating layer, the inner package layer and the outer package are heated in the heating step. A step of making a cut while sandwiching the layer with a cutter in a direction substantially perpendicular to the longitudinal direction, and a step of moving the cutter in the longitudinal direction of the optical fiber to remove the protective coating layer, the inner collective covering layer, and the outer collective covering layer. It is characterized by having.

According to the second coating removing method, the second coating removing method is used.
A method of removing a coating on an optical fiber ribbon, the method comprising: heating a second optical fiber tape; cutting a coating into the coating while sandwiching the coating in a direction substantially perpendicular to the longitudinal direction; And removing in a longitudinal direction of the core wire.

That is, in the second optical fiber ribbon, the force for pulling out the protective coating layer of the optical fiber core and the adhesion between the protective coating layer and the inner batch coating layer are limited to predetermined ranges. By heating the optical fiber ribbon, the integrity of the protective coating layer and the inner and outer collective coating layers is enhanced. In such a state, an axial pulling force is applied to the protective coating layer, the inner collective coating layer, and the outer collective coating layer, so that it becomes easier to remove these coating layers integrally as described above. Further, at room temperature, since the integrity of the collective coating layer due to the molecular motion is released, the adhesion between the collective coating layer and the protective coating layer is weakened, and the single-core separation characteristic is secured.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an optical fiber ribbon according to an embodiment of the present invention; In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description.

FIG. 1A shows an example of the configuration of an optical fiber ribbon according to the present embodiment, and FIG. 1B shows an example of the configuration of an optical fiber core used in the optical fiber ribbon. FIG. In FIG. 1, an optical fiber ribbon 5 is provided with a protective coating layer 2 provided on the outer periphery of an optical fiber (glass fiber) 1 made of quartz glass to form an optical fiber core 3 and a plurality of optical fiber ribbons 5 (FIG. 1). (A) is 4
The optical fiber core wires 3 are arranged in parallel in a plane, and the outer circumferences of these core wires 3 are integrally formed by a collective coating layer 4.
The protective coating layer 2 has a primary layer 2a made of a soft ultraviolet curable resin, a secondary layer 2b made of a hard resin on the outer periphery thereof, and a colored layer 2c provided on the outer periphery thereof in this order.

In the above-mentioned optical fiber tape 5,
Since the glass fiber 1 constituting the optical fiber core 3 is held by the protective coating layer 2, there is a lower limit of 300 g in the force for pulling out the protective coating layer 2 from the glass fiber 1 and a predetermined force in the axial direction. , An upper limit of 1700 g is required to remove the protective coating layer 2. In order to ensure the simultaneous removal of the protective coating layer 2 and the collective coating layer 4, the adhesion between the two coating layers is 0.4 g.
/ Cm is required, and an upper limit of 10 g / cm is required in order to separate the collective coating layer 4 from the protective coating layer 2 and secure the single-core separation of the optical fiber core wire 3.

In addition to the above requirements, the present inventors have conducted intensive studies to improve the collective removal of the protective coating layer 2 and the collective coating layer 4, and as a result, have found that the collective coating layer 4
The composition is adjusted such as the crosslink density, the concentration of polar groups capable of hydrogen bonding such as urethane groups, etc., so that the loss tangent becomes 0.05 or more, thereby increasing internal friction due to molecular motion, and as a result, protective coating It has been found that the integration with the layer is strengthened and the collective removal property is improved. On the other hand, at room temperature, the integrity of the collective coating layer due to the molecular motion of the protective coating layer is released, so that it is easy to remove the collective coating layer from the protective coating layer, and the single-core separation of the optical fiber core is reduced. Secured.

On the other hand, when the value of the loss tangent is less than 0.05, the internal friction due to the molecular motion becomes small, and the collective coating layer shows a hard state or a soft state.

If the coating is too hard, peeling is likely to occur between the collective coating layer and the protective coating layer when a force for removing the coating is applied in the axial direction, and the coating is brittle. Cheap. If it is too soft, it will not be able to hold the tubular shape when the collective removal force is applied, and will be bent in a bellows-like manner, leaving the protective coating layer on the glass fiber surface or breaking the glass fiber.

Next, a description will be given of a method of measuring the above-mentioned various characteristics that the optical fiber ribbon according to the present invention must have. FIG. 2A shows a state before the protective coating layer is pulled out from the glass fiber.
(B) is a diagram showing a state after pull-out. FIG.
In, the optical fiber core wire 3 is fixed on a hard plate 10 made of metal or the like with an adhesive 11. Next, a cut 12 is made in the protective coating layer 2 of the optical fiber core 3 on the hard plate 10 at right angles to the longitudinal direction, and the other end side of the optical fiber core 3 fixed to the hard plate 10 at room temperature is drummed. 13 while pulling it around. As a result, the tubular protective coating layer 2 is left on the hard plate 10 and the optical fiber 1
Only are pulled out.

The adhesive force between the protective coating layer 2 and the collective coating layer 4 is measured by molding the resin into a film.
First, a resin for forming the secondary layer 2b is applied to a thickness of 20 μm on a PET substrate, and the resin is applied in air at 100 mJ / cm ^2.
To cure. A resin for forming the colored layer 2c is applied thereon by a spin coater to a thickness of about 10 μm,
Cure at 5 mJ / cm ² . Further, the resin for forming the collective coating layer 4 is further applied thereon by about 8
Coat to a thickness of 0 μm and cure in nitrogen at 100 mJ / cm ² . The three-layer film thus produced is made of PET
Remove from the board. A part of the three-layer film between the resin forming the colored layer 2-3 and the resin forming the collective coating layer 4 is peeled to make a margin. The grip margin is subjected to a 180-degree peel test using a tensile tester to evaluate the adhesion at room temperature. The sample width is 45 mm and the tensile speed is 2
00 mm / min.

The loss tangent is the ratio between the dynamic elastic modulus G 'when the bulk coating resin is subjected to vibrational strain and the loss elastic modulus G ":
G ′ / G ″, which indicates the maximum at the glass transition point of the batch-coated resin. When the loss tangent is near the maximum value, the internal friction due to the molecular motion of the batch-coated resin becomes the maximum, and becomes smaller as it goes to both sides, and the molecular When the movement is low, it indicates a hard state or a soft state.If it is too hard, the batch coating resin is less likely to be deformed, it is easy to peel off with the protective coating layer 2, and when it is brittle, it peels off. If it is too soft, the batch coating resin layer 4 will be easily removed, and the protective coating layer 2 will remain on the surface of the glass fiber 1. From this point of view, the protective coating layer 2 is removed. In order to remove them all at once, the loss tangent of the collective coating layer in a high-temperature state needs to be 0.05 or more, as shown in Examples and Comparative Examples described below.
Preferably it is 0.07 to 0.70.

The loss tangent can be measured, for example, by using a dynamic elasticity meter: Leo Vibron manufactured by Toyo Seiki Co., Ltd., and measuring the temperature dispersion at a frequency of 11 Hz to obtain a value at a predetermined temperature. A measurement sample was cut out from the optical fiber ribbon 5 with a razor blade, and the measurement was performed with a sample length of 10 mm.

Although the optical fiber ribbon of the present invention has been described with reference to the case shown in FIG. 1, other typical structures are shown in FIGS. FIG. 3 is a diagram showing an optical fiber tape core 5a formed by arranging eight optical fiber cores 3 in parallel and integrating their outer circumferences with a collective coating layer 4. Further, FIG. 4 shows that four optical fiber cores 3 are arranged in parallel, and two optical fiber units 50 formed by integrating the outer periphery with an inner collective coating layer 4a are further arranged in parallel. This is a split type optical fiber tape core 5b having eight optical fiber cores 3 formed by integrating the outer periphery with an external collective coating layer 4b. These optical fiber ribbons are also required to have a collective removal property of the coating and a single-core separability of the optical fiber ribbon, as described above.

Next, a method of removing the coating of the optical fiber ribbon according to the present embodiment will be described. FIG. 5A is a view showing a heating step in the method of removing the coating of the optical fiber ribbon, FIG. 5B is a view showing a cutting step of the coating, and FIG. FIG.

In FIG. 5 (a), the optical fiber ribbon 5 is placed on a fixing base 20, fixed with a pressing plate 21 from above, and the tip of the optical fiber ribbon 5 is blown with hot air 22 from both sides. And heat (heating step). Heating temperature is 7
0 ° C to 110 ° C. Next, in FIG.
A cut is made in the heated optical fiber ribbon 5 in such a manner that the protective coating layer 2 and the collective coating layer 4 are sandwiched between the cutters 23a and 23b in a direction Y substantially perpendicular to the longitudinal direction (coating cutting step). Next, in FIG. 5C, the cutters 32a and 32b with the cuts are moved in the longitudinal direction X to remove the protective coating layer 2 and the collective coating layer 4 at the distal end from the glass fiber 1 (coat removal). Process).

In the optical fiber ribbon 5 used in the coating removing method of the present embodiment, the pull-out force between the glass fiber 1 and the protective coating layer 2 is limited to a predetermined value or less. Since the blanket coating layer 4 is bonded to the blanket coating layer 4 with an adhesion force of a predetermined value or more, the cutter 23 is moved in the longitudinal direction X.
When a predetermined force is applied to the glass fiber 1, the protective coating layer 2 and the collective coating layer 4 can be collectively removed from the glass fiber 1.

Further, at this time, the optical fiber ribbon is heated and in a high temperature state, and the loss tangent of the collective coating layer 4 is 0.05 or more, so that the integrity with the protective coating layer 2 is enhanced. I have. Therefore, the collective removal of both coating layers becomes more reliable.

Next, a method for separating a single optical fiber ribbon according to the present embodiment will be described with reference to FIG. First, the four-core optical fiber ribbon 5 shown in FIG. 6A is torn from the center by hand as shown in FIG.
Then, as shown in FIG.
It is taken out from the collective coating layer 4 one by one.

When the interface state between the protective coating layer 2 and the collective coating layer 4 is viewed at the atomic level, there are portions where the adhesion is strong and portions where the adhesion is weak. In moist heat, moisture starts to accumulate in weakly adhered parts, and peeling gradually spreads. However, when the loss tangent is 0.05 or more in a state where the collective coating layer 4 is heated to 70 ° C. or more as in the present invention, molecular motion occurs while maintaining a certain hardness. For this reason, water accumulates at the interface, the molecular motion relaxes the stress that tends to expand, and the spread of cracks is suppressed, so that the glass fiber has a protective effect.

Therefore, an aging test was performed on the optical fiber ribbon, and the protection effect of the collective coating layer was evaluated from the change in transmission loss before and after aging. The aging test was carried out by placing 700 m of an optical fiber tape with a length of 700 m in a thermo-hygrostat at a temperature of 85 ° C. and a relative humidity of 85% for 30 days. The protection effect was evaluated by measuring the transmission loss at a wavelength of 1.55 μm before and after aging using OTDR, and determining the difference between the two.

[0037]

EXAMPLES The present inventors, based on the above embodiment,
Prepare various optical fiber tape cores as follows,
We studied the collective removal properties of the coating, the single core separation property, and the transmission loss when aged in wet heat.

(Examples 1 to 6 and Comparative Examples 1 to 4) The produced optical fiber ribbons 5 are obtained by integrating the outer peripheries of the four optical fiber ribbons 3 shown in FIG. It is. The optical fiber core 3 has a protective coating layer 2 provided on the outer periphery of a glass fiber 1 made of quartz glass having a diameter of 125 μm. The protective coating layer 2 includes a primary layer 2a made of a soft UV-curable resin on the outer periphery of the glass fiber 1, a secondary layer 2b made of a hard UV-curable resin outside the primary layer 2a, and a hard layer outside the secondary layer 2b. The discrimination layer 2c to which the ultraviolet curable ink was added was formed.

The soft UV-curable resin used as the primary layer 2a is composed of P-1, P-2 and P- by adjusting the amount of the silane coupling agent of the urethane acrylate resin and the type and amount of the monomer. 3, P-4 and P-11 were prototyped.

As the hard ultraviolet curing resin used as the secondary layer 2b, a urethane acrylate resin was used.

The hard UV-curable ink used as the discriminating layer 2c uses an epoxy acrylate resin, and adjusts the types and amounts of the monomer and the release agent to obtain C-1 and C-.
2 was prototyped.

The UV-curable resin used as the batch coating layer 4 is adjusted in composition so as to change the crosslink density and urethane group concentration of the urethane acrylate resin in order to change the loss tangent, so that R-1 and R-1 are changed. -2, R-3, R-
4, R-11, R-12, R-13, R0-1, R0-
2, R0-11 was prototyped.

With respect to the optical fiber ribbon 5 produced by combining these resins, collective coating removal property, single-core separation property and aging were evaluated by the above-described methods. Table 1 shows the resin used for the optical fiber ribbon 5 and the measurement results.

[0044]

[Table 1]

The evaluation of the collective coating removal property was such that no residue of the inner resin coating remained on the surface of the glass fiber after the coating was removed in a high temperature state, and the removed protective coating layer and the collective coating layer were not removed. Pass / fail was determined on the basis of maintaining a substantially pipe shape. In addition, the evaluation of the single-core separation property is that when the collective coating layer is removed at a normal temperature state for the leading end portion of the tape core wire at 50 mm, the coloring layer does not peel off, and no residue of the collective coating layer remains on the surface of the coloring layer. Pass / fail was determined on the basis of.

In Examples 1 to 6, the pull-out force between the glass fiber and the protective coating layer was 700 to 1600.
g, and the adhesive strength between the protective coating layer and the collective coating layer is 0.5
9.1 g / cm, and the loss tangent of the collective coating layer at a temperature of 90 ° C. was 0.06 or more. As a result of performing a collective removal of the coating and a single-core separation test on these optical fiber ribbons, All were good.

Next, as shown in Comparative Example 1, when the coating was removed by increasing the pull-out force to 1800 g, a case where the primary layer remained on the surface of the glass fiber appeared. Further, as shown in Comparative Example 2, when the coating was removed when the adhesive force between the protective coating layer and the collective coating layer was 0.3 g / cm, the collective coating layer was peeled off and the protective coating layer remained on the glass fiber. When the adhesive force was 13 g / cm, as shown in Comparative Example 3, the collective coating removal was good, but when the single core was separated, the colored layer was peeled off and could not be separated smoothly. . Further, Comparative Example 4
As shown in the figure, when the loss tangent of the batch coating layer at a temperature of 90 ° C. was 0.03 and the batch removal test of the coating was performed, it was found that the batch coating layer was peeled off and the protective coating layer remained on the glass fiber. .

Further, an aging test was also performed on each of the above-mentioned optical fiber ribbons, and a change in transmission loss before and after aging was measured. As a result, as shown in Table 1, the transmission loss hardly changed in Examples 1 to 5 and Comparative Examples 1 to 3, but the loss increased in Comparative Example 4.

(Examples 7 to 9 and Comparative Examples 5 to 8)
As shown in FIG. 4, the four optical fiber cores 3 are integrally formed with the inner collective coating layer 4a to form an optical fiber unit 50. The two optical fiber units 50 are arranged in a plane, and are arranged on the outer periphery thereof. A split-type optical fiber ribbon 5b having eight optical fiber cores 3 was formed integrally with the external collective coating layer 4b. The optical fiber core 3 and the resin for coating are the same as those used in the first embodiment. The optical fiber tape core wire 5b thus manufactured was subjected to a batch removal of coating and a single core separation test. Table 2 shows the resin used for the optical fiber ribbon 5b and the measurement results.

[0050]

[Table 2]

In Examples 7 to 9, the pull-out force between the glass fiber and the protective coating layer was 400 to 800 g.
And the adhesive strength between the protective coating layer and the collective coating layer is 0.5 to
0.9 g / cm, and the loss tangent of the collective coating layer at a temperature of 90 ° C. was 0.15 or more. As a result of performing collective coating removal and single-core separation on these optical fiber ribbons, all were good. Met.

Next, as shown in Comparative Example 5, when the coating was removed by increasing the pull-out force up to 1800 g, the primary layer remained on the glass fiber surface. Further, as shown in Comparative Example 6, when the protective coating layer and the collective coating layer were coated and removed with an adhesive force of 0.3 g / cm, the collective coating layer was peeled off and the protective coating layer remained on the glass fiber. And as shown in Comparative Example 7,
When the adhesive strength was 13 g / cm, the collective coating removal was good, but a single-core separation test showed that the colored layer was peeled off and smooth separation was not possible. Comparative Example 8
As shown in the above, the batch removal test at a temperature of 90 ° C. with the loss tangent of the batch coating layer set to 0.04 revealed that the batch coating layer was peeled off and the protective coating layer remained on the glass fiber.

[0053]

According to the optical fiber ribbon of the present invention, the force for pulling out the protective coating layer of the optical fiber core and the adhesion between the protective coating layer and the collective coating layer are limited to predetermined ranges. Therefore, it is possible to remove both coating layers at once, and by increasing the loss tangent of the collective coating layer at high temperatures, the integrity of the collective coating layer and the protective coating layer at high temperatures is enhanced. As a result, collective removal can be improved. On the other hand, at room temperature, the integrity of the collective coating layer and the protective coating layer is released, so that the single-core separation at room temperature is ensured.

According to the coating removing method of the present invention, the optical fiber ribbon having the above characteristics is removed after heating.
Collective removal of the coating layer is improved.

[Brief description of the drawings]

FIG. 1A is a diagram showing an entire configuration of a first optical fiber ribbon according to the present embodiment, and FIG. 1B is a diagram showing an optical fiber ribbon used for the optical fiber ribbon. FIG.

FIG. 2A is a diagram showing a state before the protective coating layer is pulled out from the glass fiber, and FIG. 2B is a diagram showing a state after the protective coating layer is pulled out.

FIG. 3 is a view showing another optical fiber ribbon according to the embodiment;

FIG. 4 is a view showing a second optical fiber ribbon according to the embodiment;

5 (a) is a view showing a heating step in the method of removing the coating of the optical fiber ribbon, FIG. 5 (b) is a view showing a cutting step of the coating, and FIG. 5 (c) is a drawing of the coating. It is a figure which shows a batch removal process.

FIG. 6 is a diagram showing a method for separating a single optical fiber ribbon.

FIG. 7 is a diagram showing a conventional optical fiber ribbon.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass fiber, 2 ... Protective coating layer, 2a ... Primary layer, 2b ... Secondary layer, 2c ... Colored layer, 3 ...
・ Optical fiber core wire, 4 ・ ・ ・ Batch layer, 4a ・ ・ ・ Batch layer, 4b ・ ・ ・ Batch layer, 5, 5a, 5b, 5
c: optical fiber ribbon, 10: hard plate, 11:
Adhesive, 12 ... cut, 13 ... drum, 14 ... arrow, 20 ... fixed base, 21 ... holding plate, 22 ... heat, 2
3 ... cutter, 50 ... optical fiber unit, X, Y ...
direction.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H001 BB15 BB19 BB22 BB27 BB28 KK02 PP01 2H038 CA02 CA04 5G353 AB06 AC05 BA02 CA04 DA02 EA04

Claims (5)

[Claims] 1. An optical fiber ribbon, wherein a plurality of optical fiber cores provided with a protective coating layer on the outer periphery of a glass fiber are arranged in parallel, and the outer periphery is integrally formed by a collective coating layer. The pull-out force between the glass fiber and the protective coating layer is 300 g or more and 1700 g or less, and the adhesion between the protective coating layer and the collective coating layer is 0.4 g.
/ Cm or more and 10 g / cm or less, and the loss tangent of the collective coating layer at 70 ° C to 110 ° C is 0.05 or more. 2. A plurality of optical fiber units in which a plurality of optical fibers having a protective coating layer provided on the outer periphery of a glass fiber are arranged in parallel, and the outer periphery thereof is integrated with an inner collective coating layer. Further, in the optical fiber ribbon formed by arranging in parallel and integrating the outer periphery with an external collective coating layer, a pull-out force between the glass fiber and the protective coating layer is 300 g or more and 1700 g or less, The adhesion between the protective coating layer and the inner batch coating layer is 0.
An optical fiber ribbon comprising: 4 g / cm or more and 10 g / cm or less; and a loss tangent of the inner collective coating layer and the outer collective coating layer at 70 ° C to 110 ° C of 0.05 or more. 3. A plurality of optical fibers having a protective coating layer provided on the outer periphery of a glass fiber are arranged in parallel, and the outer periphery is integrally formed by a collective coating layer. The pull-out force between the coating layer and the protective coating layer is 300 g or more and 1700 g or less, and the adhesion between the protective coating layer and the collective coating layer is 0.4 g / cm or more and 10 g.
/ Cm or less, and further comprising a step of heating the optical fiber ribbon, wherein the loss tangent of the batch coating layer at 70 ° C to 110 ° C is 0.05 or more. A step of making a cut while sandwiching the protective coating layer and the collective coating layer heated in the heating step in a direction substantially perpendicular to the longitudinal direction with a cutter, and moving the cutter in the longitudinal direction of the optical fiber core wire. Removing the protective coating layer and the collective coating layer from each other. 4. A plurality of optical fiber units in which a plurality of optical fibers having a protective coating layer provided on the outer periphery of a glass fiber are arranged in parallel, and the outer periphery is integrally formed by an inner collective coating layer. Are arranged in parallel, the outer periphery thereof is integrally formed by an external collective coating layer, and the pull-out force between the glass fiber and the protective coating layer is 300.
g to 1700 g, and the adhesion between the protective coating layer and the inner batch coating layer is 0.4 g / cm to 10 g / g.
cm or less, and wherein the loss of the loss tangent of the inner collective coating layer and the outer collective coating layer at 70 ° C. to 110 ° C. is 0.05 or more. A step of heating a wire; a step of cutting the protective coating layer, the inner collective coating layer, and the outer collective coating layer heated in the heating step while sandwiching the protective coating layer with a cutter in a direction substantially perpendicular to a longitudinal direction; Removing the protective coating layer, the inner collective coating layer and the outer collective coating layer by moving the optical fiber ribbon in the longitudinal direction of the optical fiber core. Removal method. 5. The method according to claim 3, wherein the heating step heats the optical fiber ribbon to 70 ° C. to 110 ° C.